The first issue is maintaining a connection. No router is perfect, and every router drops a signal now and then. Now consider how temperamental some wireless cards can be, particularly with the routers distributed by many popular ISPs. Consider also the possibility of interference from microwave units and other appliances, or even from sources outside your building. Using a cable can be more attractive if you’re planning on making large uploads, for instance, or if you need a steady continuous connection for voice over IP or gaming.
The second issue is speed. A wireless card can only support so much data at a time. This is another reason to turn to wired connections, possibly using cat5 cables at TriangleCables. This isn’t a concern for most people, but anyone involved in the production of music or videos can attest that bandwidth matters even when you aren’t uploading your content to the web.
There are many attractive reasons to switch from wireless to wired. Wifi works just fine most of the time, but the instances where it falls short are more than enough to drive many to look into the necessary cables for wired solutions.